Accessing variable by pointer in OpenCL kernel

Question

I am writing a raytracing program in OpenCL and I have a function in my Kernel, Quadratic, that takes in 3 float variables and two pointers to float values.

Function:

bool Quadratic(float A, float B, float C, float *t0, float *t1) {
    float discrim  = B * B - ( 4.0 * A * C );
    if (discrim <= 0.0) return false;
    float rootDiscrim = sqrtf(discrim);
    float q;
    if (B < 0) q = -0.5f * ( B - rootDiscrim);
    else q = -0.5f * ( B + rootDiscrim);
    *t0 = q / A;
    *t1 = C / q;
    float temp;
    return true;
}

Calling the Function:

float t0;
float t1;
if (Quadratic(A,  B,  C,  &t0,  &t1)) c[(i*dimy)+j] = t0;
else c[(i*dimy)+j] =  0.0;

Produces the following error:

pyopencl.RuntimeError: clBuildProgram failed: build program failure - 
Build on <pyopencl.Device 'ATI Radeon HD 6750M' on 'Apple' at 0x1021b00>:
Error returned by cvms_element_build_from_source

In trying to work out what the problem was I created the following test function which seems to work:

bool TestFunc(float Y, float *x) {
    *x = Y;
    return true;
}

float x;
if (TestFunc(50.0, &x)) c[(i*dimy)+j] = x;

As far as I can see both functions have the same types of inputs and outputs, any help would be greatly appreciated.

Answer 1

It turns out the problem was with using sqrtf. Once changed to sqrt it works perfectly.